Apparatus and methods for selective removal of material from wafer alignment marks

ABSTRACT

A process and apparatus for locally removing any material, such as a refractory metal, in particular tungsten, from any desired area of a wafer, such as an alignment mark area of a silicon wafer in process during the formation of integrated circuits thereon.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 10/647,634,filed Aug. 25, 2003, now U.S. Pat No. 7,244,681, issued Jul. 17, 2007,which is a continuation of application Ser. No. 09/944,471, filed Aug.30, 2001, now U.S. Pat. No. 6,610,610, issued Aug. 26, 2003, which is acontinuation of application Ser. No. 09/639,421, filed Aug. 14, 2000,now U.S. Pat. No. 6,329,301, issued Dec. 11, 2001, which is acontinuation of application Ser. No. 08/916,997, filed Aug. 20, 1997,now U.S. Pat. No. 6,103,636, issued Aug. 15, 2000. The disclosure ofeach of the previously referenced U.S. patent applications and patentsreferenced is hereby incorporated by reference in its entirety. Thisapplication is also related to application Ser. No. 09/567,631, filedMay 9, 2000, now U.S. Pat. No. 6,447,634, issued Sep. 10, 2002,application Ser. No. 10/154,582, filed May 24, 2002, now U.S. Pat. No.6,530,113, issued Mar. 11, 2003 and application Ser. No. 10/367,224,filed Feb. 14, 2003, now U.S. Pat. No. 6,889,698, issued May 10, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to improved semiconductor processing technology.More specifically, the present invention relates to an improved processand apparatus for locally removing any desired material frompredetermined areas of a silicon wafer in process during the formationof integrated circuits thereon, such as the removal of material from thewafer alignment mark areas of a silicon wafer.

2. State of the Art

The fabrication of integrated circuits on silicon wafers utilizes manydiffering processes and materials. For instance, photolithographictechniques are used to pattern the various gates on the silicon chip. Assophisticated pattern definition technologies have been used, thegeometries of the integrated circuit components have shrunk from the 6micron size of the late 1970s to the submicron technologies of the late1980s to the deep submicron regions of the 1990s. Therefore, it hasbecome increasingly important to carefully align the wafer duringsemiconductor device manufacturing processes. Also, as the size of thefeatures of the integrated circuits has become increasingly smaller andthe spacing of the semiconductor devices has decreased on the wafer, outof necessity, the size of any predetermined area of the wafer containingany feature or circuit component on the wafer has decreased. Forinstance, the alignment marks on the wafer used to align the waferduring manufacturing processes and the area surrounding the alignmentmarks on the wafer have become increasingly smaller.

Due to various constraints in semiconductor device manufacturingprocesses, it is critical that predetermined areas of the wafer be freeof material contamination during the process. As an example, thealignment marks on the wafer should be kept free of contaminants so thatthe process equipment can easily locate and use such alignment marks. Invarious semiconductor manufacturing processes, the alignment marks caneasily become contaminated or covered with various process materials. Insuch instances, it is necessary to clean the alignment marks on thewafer before any subsequent processing occurs to ensure proper alignmentof the wafer on the process equipment.

As one example of such process problems, after the application of aphotoresist material used in a circuit forming process and thesubsequent etching of the wafer to form the desired circuit or portionthereof, the alignment marks on the wafer may be covered withphotoresist material which must be removed prior to the continuedprocessing of the wafer.

As another example, a chemical mechanical planarization process is thepreferred method of planarizing various films and coatings on wafers.However, a chemical mechanical planarization process does notnecessarily uniformly remove material from the wafer surface due toeither dishing of the polishing pad caused by surface irregularities onthe wafer and/or the non-uniform application of the polishing slurryover the wafer surface. Such problems occur, particularly, when using achemical mechanical planarization process to remove refractory metalfilms and the like. Since the refractory metal film is not of uniformthickness, the refractory metal film may not be removed in the areas ofthe wafer where alignment marks are present or other predetermined areasof the wafer. Furthermore, the alignment marks, or other predeterminedareas, on the wafer may also be covered with slurry material used in thechemical mechanical planarization process or have residual refractorymetal film remain which has not been removed during the chemicalmechanical planarization process thereon, thereby obscuring thealignment marks. Therefore, it is desirable to have a method andapparatus for cleaning predetermined areas of the wafer, such as thealignment marks of wafers, after chemical mechanical planarizationprocesses thereon.

As an example of such wafer process problems discussed above, thefabrication of multi-level interconnections in integrated circuits hasbeen facilitated through the use of tungsten, a refractory metal.However, tungsten is difficult to etch selectively because the surfaceof most tungsten films deposited using chemical vapor depositiontechniques is rough and because tungsten and silicon dioxide formvolatile fluoride compounds. Due to such problems, it is difficult toselectively etch tungsten to remove the unwanted tungsten that remainson the low areas of the wafer surface, such as those areas wheresemiconductor devices are being formed, or in predetermined areas of thewafer, such as those areas of the wafer surface where alignment marksexist.

Since a tungsten film covers the surface of semiconductor devices beingformed on the wafer surface, the tungsten film must be etched backselectively so that the tungsten film only remains in the vias orcontact holes to eliminate the tungsten film in the low areas of thewafer surface. Several methods use either a photoresist or a polyimidesacrificial film to planarize the tungsten film. Using these methodsrequires the sacrificial film to be highly planarized, followed by anover-etch to clear all of the tungsten film from the low areas of thewafer surface that are present after the planarization of the wafersurface. Since tungsten etching is difficult to control to produce auniform surface on the wafer, over-etching is often required to insuretungsten removal. However, over-etching can result in recessed tungstenplugs which interconnect the integrated circuitry being formed on thewafer in process, particularly when the wafer is not of uniformthickness. Additionally, over-etching may not remove the tungsten fromall low areas of the wafer surface, such as those areas where thealignment marks of the wafer are present or other predetermined areas ofthe wafer.

In a prior art process, described in U.S. Pat. No. 5,271,798, a methodfor the selective etching of the alignment mark areas of the wafer isset forth to selectively etch the alignment mark areas of the waferusing a wet etching process which can be controlled and isolated to aspecific area of the wafer. In the prior art process, tungsten isselectively etched locally from the alignment marks on the wafer eitherbefore or after the chemical mechanical planarization process. Thewafers are flat aligned and a tungsten etch solution is introducedthrough an enclosed etchant-dispensing apparatus onto low-lying areas ofthe wafer surface which result from the alignment marks used foraligning various photolithography mask steps. Since the alignment marksare normally a few hundred microns in size and if a large amount ofunused silicon area exists around the alignment marks, the alignmentarea constraints regarding an enclosed etchant-dispensing apparatus andwafer are not too severe. Also, when a large amount of unused siliconarea exists around the alignment marks, the tungsten plugs in thesemiconductor device being formed on the wafer can be easily protectedfrom the wet etch. Either during or after the etch, the etching productsare removed and the wafers are cleaned by being rinsed in distilledwater.

In U.S. Pat. No. 5,271,798, a method and apparatus is illustrated forthe cleaning of alignment marks on a wafer. The apparatus illustrateduses a cylindrical containment apparatus having a seal on the bottomthereof to sealingly engage the area surrounding the alignment mark on awafer. An etchant is dispensed through the containment apparatus ontothe alignment mark on the wafer to etch contaminants therefrom with theetchant being removed from the alignment mark area by a vacuum. Such aprior art method and apparatus require a physical contact seal betweenthe containment apparatus and the wafer area surrounding the alignmentmark which may cause damage to the surface of the wafer or surroundingsemiconductor devices being formed on the wafer.

However, as discussed previously, with the increasing density ofsemiconductor devices formed on the wafer surface, the area availablefor the placement of semiconductor devices and the surroundingpredetermined areas of the wafer which must be kept clean during waferprocessing has decreased. For example, the alignment marks and theunused silicon area surrounding the alignment marks have decreased foruse of the etching equipment during the removal of material from thealignment marks of the wafer.

Therefore, a need exists for an improved method and apparatus for thereliable etching of any material, such as a photoresist material,chemical mechanical planarization process materials, a refractory metal,etc., from predetermined areas of the wafer and the surrounding areas,such as the alignment marks on wafers, without damage to the surroundingwafer area or the circuitry components on the wafer.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to an improved process and apparatusfor locally removing material from predetermined areas of the wafer,such as the wafer alignment mark areas of a silicon wafer in processduring the formation of integrated circuits thereon. A process andapparatus of the present invention locally removes material frompredetermined areas of the wafer, such as the wafer alignment mark areasof a silicon wafer, in process during the formation of integratedcircuits thereon without contacting the area surrounding thepredetermined area of the wafer, such as the alignment mark of thewafer, while maintaining the etching material within the predeterminedarea, such as the alignment mark area, to prevent damage to thesurrounding semiconductor circuits. The process comprises the steps ofaligning the predetermined area, such as the alignment marks, on thewafer to an etchant-dispensing apparatus, positioning a portion of theetchant-dispensing apparatus adjacent the surface of the wafer at thepredetermined area, dispensing at least one etchant agent onto thepredetermined area, such as the alignment mark, and removing any etchingagent or cleaner or rinse material from the wafer. The apparatus for thecleaning of an area of a semiconductor wafer using a material comprisinga tube having a bore therethrough and exterior wall, the tube supplyinga material to the area of the wafer and an annular member having aninterior wall surrounding the tube, the annular member having a thinannular edge thereon for positioning adjacent a portion of thepredetermined area of the wafer, such as the alignment mark area of thewafer, during the cleaning thereof, the annular member forming anannular space between the tube and the interior wall of the annularmember.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a portion of a wafer in process;

FIG. 2 is a cross-sectional view of a portion of a wafer in process witha portion of the apparatus of the present invention;

FIG. 2A is a cross-sectional view of a portion of a wafer in processwith a portion of the apparatus of the present invention illustratedhaving a modified thin annular edge thereon;

FIG. 3 is a cross-sectional view of a portion of a wafer in processhaving the area of the alignment marks being cleaned by the apparatusand method of the present invention;

FIG. 4 is a first side view of the cleaning apparatus of the presentinvention;

FIG. 5 is a top view of the cleaning apparatus of the present invention;

FIG. 6 is a second side view of the cleaning apparatus of the presentinvention;

FIG. 7 is a third side view of the cleaning apparatus of the presentinvention; and

FIG. 8 is a top view illustrating a localized etchant-dispensingapparatus aligned to a wafer and positioned at alignment marks thatreside on the wafer.

DETAILED DESCRIPTION OF THE INVENTION

Referring to drawing FIG. 1, a silicon wafer 10 has an overlying layer 1of borophosphosilicate glass (BPSG) in which patterns for circuits havebeen etched exposing silicon wafer 10 at alignment marks 12 on the wafer10, a predetermined area of the wafer. A material has been formed overthe wafer surface and the surface planarized, typically using a chemicalmechanical planarization process leaving residue 13 at the alignmentmarks 12, a predetermined area of the wafer, on the wafer 10. Typically,a refractory metal, tungsten will have been deposited by chemical vapordeposition over the wafer surface and the surface planarized using achemical mechanical planarization process leaving residue 13 at thealignment marks 12 on the wafer 10 or other predetermined areas of thewafer. The residue 13 may include the chemical mechanical planarizationprocess slurry material, a refractory metal residue, a photoresistresidue, a dielectric material residue, a polysilicon material residue,etc.; for example, any residue from a semiconductor manufacturingprocess may be present in the alignment marks 12 on the wafer 10 to beremoved therefrom or from any desired predetermined area of the wafer.

Referring to drawing FIG. 2, the wafer 10 is mounted in a substantiallyflat alignment (horizontal, perpendicular alignment) prior to the localdispersion of a wet etching agent to remove residue 13. The wet etchingagent may comprise well-known etching agents, such as liquid, liquidvapor, gases, etc., examples of such including ammonia, hydrogenfluoride, nitric acid, hydrogen peroxide, ammonium fluoride, etc. Theetchant may be heated, if desired, by any suitable source, such asultrasonic energy, laser heating, etc. The wafer surface overlying layer11 must be positioned in relation to apparatus 21 such that lower thinannular edge 22, an annular type knife edge of the apparatus 21, ispositioned adjacent layer 11, but not in contact with layer 11, toprovide a “virtual” seal or vacuum therewith. An etching agent isintroduced through a tubular member 52, a needle-like member ofetchant-dispensing apparatus 21 (also referred to as “etching apparatus”or “cleaning apparatus” 21) onto the alignment marks 12 on the wafer 10to remove the residue 13. Since the alignment mark 12 is a few hundredmicrons in size and little unused area exists on the wafer 10surrounding the mark 12, the constraints regarding the size and use ofthe etching apparatus 21 are severe in order to ensure that anysemiconductor circuit components in the electronic circuitry located onthe wafer 10 surrounding an alignment mark 12 are protected from theetching process. The etching apparatus 21 is an enclosed apparatus withthe thin annular edge 22 thereof creating a “virtual” seal or vacuumwith the underlying glass (BPSG) layer 11 by a suction being appliedthrough annular space 56 formed between the interior annular wall ofannular member 54 and the exterior wall of tubular member 52 of theetching apparatus 21. Sufficient suction is applied in the annular space56 so that the pressure of the existing atmosphere surrounding theexterior of the thin annular edge 22 is greater than the pressure in theannular space 56 with the existing atmosphere surrounding the thinannular edge 22 being drawn into the annular space 56 between thetubular member 52 and annular member 54, thereby preventing any leakageof etchant from the annular space 56. The thin annular edge 22 of theetching apparatus 21 does not contact the surface of the layer 11,thereby preventing any damage thereto. The surrounding atmosphere of theannular member 54 flows into the gap formed between the lower edge ofthin annular edge 22 and the surface of layer 11 (illustrated by thearrows entering into annular space 56 in drawing FIG. 2) creating the“virtual” seal or vacuum between the etching apparatus 21 and the layer11, thereby preventing any etchant material being used from flowing fromthe annular space 56 onto the surrounding area of layer 11 of theexterior to annular member 54. The thin annular edge 22 is located asclose as possible to the surface of the layer 11 on the wafer 10 withoutbeing in contact therewith.

Referring to drawing FIG. 2A, if desired, more than one thin annularedge 22 may be used on the end of annular member 54 to create alabyrinth type “virtual” seal to more effectively prevent any fluid flowfrom the gap between the end of the annular member 54 and the surface ofthe layer 11. Such a labyrinth type thin annular edge 22′ is illustratedin drawing FIG. 2A as having two thin annular edges 22′ formed on thebottom of the annular member 54.

In both the thin annular edge 22 and the labyrinth type thin annularedge 22′, neither contacts the surface of the layer 11 to prevent theflow of etchant from the annular space 56 onto the surface of the layer11 exterior to the annular member 54. But rather, the suction or vacuumapplied to the annular space 56 draws the atmosphere surrounding theexterior of the annular member 54 into the annular space 56, therebypreventing any substantial leakage of any material in the annular space56 to the exterior of the annular member 54. Additionally, it should beunderstood that the annular space 56 refers to any shape annular areaformed between any two geometrically shaped members. That is, thetubular member 52 may have any desired cross-sectional geometric shape,such as cylindrical, hexagonal, square, octagon, ellipsoid, etc., andthe annular member 54 may have any desired cross-sectional geometricshape, such as cylindrical, hexagonal, square, octagon, ellipsoid, etc.,and the annular area 56 formed therebetween by such shaped members willhave any resulting cross-sectional configuration.

Alignment between wafer 10 and etchant-dispensing apparatus 21 may beaccomplished by any suitable well known aligning and maneuveringtechniques for aligning the wafer 10 into position. Though it ispreferred that the wafer is at a 90° angle, perpendicular to the etchingapparatus 21, the orientation of the wafer 10 and etching apparatus 21can be any desired position as long as the thin annular edge 22 or 22′of the etching apparatus 21 is located substantially adjacent, but notin contact with, the surface of the layer 11 on the wafer 10. Etchingby-products are removed by suctioning or vacuuming them from thealignment mark 12 through annular space 56 formed between the interiorannular wall of annular member 54 and the exterior wall of tubularmember 52 of the etching apparatus 21.

Referring to drawing FIG. 3, residue 13 (shown in FIGS. 2 and 2A) hasbeen removed from alignment marks 12 and the etching by-products removedby suction applied through annular space 56 of the etching apparatus 21.In addition to the removal of etching by-products from the alignmentmark 12 on the wafer 10 using suction through annular space 56, theremoval of the etching by-products may be performed during the step ofremoving etching residue 13 (in situ) from alignment mark 12 by flowingwater, or any desired cleaning material or agent or rinsing material oragent, into the etchant-dispensing apparatus 21 after dispensing theetching agent therethrough to have such wash the residue from thealignment mark 12. Once the etching by-product is removed, wafer 10 isthen cleaned by rinsing it with deionized water or other suitable wellknown cleaning or rinsing agents.

Alternately, the selective etching of any material in the alignmentmarks 12 may be performed prior to planarization of the layer 11.Performing the selective etch prior to planarization of the layer 11 hasan advantage in that the planarization removes any contaminants whichmay have been added on the wafer surface during selective wet etching ofthe alignment marks 12 (free from oxide or other particles).

Referring to drawing FIG. 4, the cleaning head 50 of the cleaningapparatus 21 previously described herein is shown. The cleaning head 50comprises a cylindrical body 51 having an elongated annular member 54 onthe end of the stem 62 thereof, having in turn, thin annular edge 22located thereon for engaging the surface of the wafer 10 and tubularmember 52 located therein for supplying the etching products to thealignment mark 12 of the wafer 10. The cylindrical body 51 comprises agenerally cylindrical head 60 and a generally cylindrical stem 62 havingelongated annular member 54 thereon. Cylindrical head 60 includes aplurality of bores 64 therein, each bore 64 having threaded aperture 66thereon for connection to a supply line (not shown), through whichetching products are supplied during the etching process, one or morebores 68, each bore 68 having an intersecting blind bore 70 connectingtherewith which is connected to a suitable source of suction or vacuum,through which etching by-products are suctioned or vacuumed from thealignment marks 12 on the wafer 10 during the etching of materialtherefrom and a bore 72 which intersects with bores 64 and within whichis contained tubular member 52 which, in turn, supplies etching productsto the alignment mark 12 of the wafer 10 during the etching of materialtherefrom. The stem 62 of the cleaning head 50 includes the lower end 74of bore 68 extending from cylindrical head 60, bore 76, the wall ofwhich forms annular space 56 with respect to the exterior wall oftubular member 52, and elongated annular member 54 on the end thereofhaving thin annular edge 22 or 22′ (see FIG. 2A) thereon which islocated adjacent, but not in contact with, the surface of the wafer 10or any layer 11 on the wafer 10 which has the alignment marks 12 thereonhaving material removed therefrom, in turn, during etching. As shown,the tubular member 52 extends throughout the bore 76 forming the annularspace 56 for the removal of etching products using a suction or vacuumsource during the etching of the alignment marks 12 of the wafer 10. Thecleaning head 50 may be made of any suitable material, may be formed ofany desired number of pieces for the convenience of assembly, cleaning,or replacement thereof, and may be formed in any desired geometricshape. The tubular member 52 typically comprises hypodermic needle stocktubing, such as a 24 gage, i.e., 0.022 inch in external diameter,standard hypodermic needle stock tubing, although any suitable tubingmay be used, such as Teflon® tubing, glass tubing, polymeric tubing,etc. Furthermore, the tubular member 52 may have any desired geometriccross-sectional shape, such as cylindrical, hexagonal, square,octagonal, ellipsoid, etc.

Referring to drawing FIG. 5, the cleaning head 50 is shown in a top viewto illustrate the orientation of the various bores therein. As shown,the bores 64, each having threaded aperture 66 thereon, are generallyspaced sixty degrees (60°) from each other and extend horizontallywithin the head 60 intersecting bore 72 therein. Although the bores 64have been illustrated as located generally sixty degrees from eachother, they may be located in any desired spacing. The blind bore 70intersects bore 68 of the head 60 to allow a source of vacuum to besupplied to the cleaning apparatus 21 during the use thereof to removethe etching products from the alignment marks 12 on the wafer 10 duringthe etching thereof. The bore 72 extends vertically within thecylindrical head 60, having the tubular member 52 being retained thereinby any suitable means, such as an interference fit, adhesively bonded,etc.

Referring to drawing FIG. 6, the cleaning head 50 is shown in a sideview to further illustrate the various bores therewithin. Asillustrated, the various bores 72 and 76 are concentrically locatedwithin cylindrical head 60 and stem 62. The thin annular edge 22 on theelongated annular member 54 of the stem 62 is formed by forming achamfered annular surface having an included angle of approximatelyninety degrees (90°) therein. Although a ninety degree angle has beenillustrated, the angle may be formed at any convenient angle which willprovide a thin annular edge 22 on the elongated annular member 54 forbeing located adjacent the surface of the wafer 10 or any layer 11located on the wafer 10 during the etching of the alignment marks 12thereon to remove material therefrom. The thin annular edge 22 does notneed to provide a fluid tight seal with respect to the wafer surface,but rather creates or forms a “virtual” seal or vacuum with respect tothe wafer surface or the surface of a layer 11 on the wafer 10, becausea sufficient amount of suction or vacuum is used to remove the etchingproducts from the alignment marks 12 being etched so that the gap orspace existing between the thin annular edge 22 and the layer 11 on thewafer 10, and the surrounding atmosphere, typically air, will be drawninto the annular area 56, thereby preventing any etching products fromescaping from the gap or space. In this manner, in contrast to the priorart, no fluid tight seal or resilient fluid tight seal is needed on theend of the elongated annular member 54 of the stem 62, therebyeliminating all problems associated with the formation and maintenanceof a fluid tight seal or resilient fluid tight seal thereon and, moreimportantly, any damage a fluid tight seal or resilient seal causes tothe surface of the wafer 10 or any layer 11 on the wafer 10.

Referring to drawing FIG. 7, the cleaning head 50 is shown in anotherside view to illustrate the relationship of the various bores 64, 68,72, 76, and the lower end 74 of the bore 68 and the intersection thereofwith bore 76. Again, the bores 72 and 76 are concentrically, verticallylocated within the cylindrical head 60 and stem 62 of the cleaning head50.

Referring to drawing FIG. 8, the cleaning apparatus 21 is schematicallyillustrated during the cleaning of alignment marks 12 on a wafer 10.Each cleaning apparatus 21 has a plurality of lines 80, each line 80being connected to threaded aperture 66 to supply etching product to thecleaning head for the cleaning of an alignment mark 12 on the wafer 10,while each cleaning head also has vacuum line 82 connected to blind bore70 to supply suction or vacuum to the cleaning head 50 to remove etchingproducts from the cleaning head. It should be noted that the presentinvention contemplates either moving the cleaning head 50 to analignment mark 12 on a wafer 10 to perform the cleaning of the alignmentmark 12 or moving the alignment mark 12 on the wafer 10 to a fixed orstationary location of the cleaning head 50. All that is necessary is tohave the cleaning head 50 located above and surrounding the alignmentmark 12 on a wafer 10 during operation for the cleaning of the alignmentmark 12.

Although the present invention has been described with respect to theembodiment, it will be apparent that changes and modifications, such asthe selective etching of any material using any desired number ofetching products supplied through any desired number of lines to thecleaning apparatus, may be made without departing from the spirit andscope of the invention. Additionally, the apparatus and method may beused to selectively etch any predetermined area of a wafer to remove anymaterial therefrom, using any desired etching products which may beheated or cooled during their use. If desired, the wafer as well as theapparatus may be heated or cooled during use.

1. A method for material removal from a surface of a wafer comprising: placing at least one thin annular edge of an annular member forming a portion of a head of an etchant dispensing apparatus adjacent a portion of the surface to remove material from the surface of the wafer; providing an etchant to a tube having a bore therethrough and located within the annular member through at least one of a plurality of inlets to the tube; dispensing the etchant through the tube onto the portion of the surface; and removing the etchant by applying a vacuum to an annular space formed between an exterior wall of the tube and an interior wall of the annular member using a source of vacuum connected to the annular space.
 2. The method of claim 1, wherein placing the at least one thin annular edge of the annular member adjacent the portion of the surface includes: aligning the wafer in a substantially perpendicular position in relation to the thin annular edge of the annular member of the etchant dispensing apparatus.
 3. The method of claim 1, wherein placing the at least one thin annular edge of the annular member adjacent the portion of the surface comprises placing a plurality of thin annular edges of the annular member adjacent the portion of the surface.
 4. The method of claim 1, wherein removing the etchant by applying the vacuum to the annular space formed between the exterior wall of the tube and the interior wall of the annular member using the source of vacuum connected to the annular space comprises forming a virtual seal between the annular member and the wafer.
 5. The method of claim 1, wherein providing the etchant and dispensing the etchant include providing and dispensing at least one of a liquid, a liquid vapor, and a gas comprising ammonia, hydrogen fluoride, nitric acid, hydrogen peroxide, ammonium fluoride, and mixtures thereof.
 6. The method of claim 1, further comprising: providing a cleaning agent to the tube and dispensing the cleaning agent through the tube after providing the etchant and dispensing the etchant.
 7. The method of claim 6, wherein providing the cleaning agent to the tube and dispensing the cleaning agent through the tube comprises providing water to the tube and dispensing water through the tube.
 8. The method of claim 1, further comprising cleaning the wafer by rinsing the wafer with a rinsing agent.
 9. The method of claim 8, wherein cleaning the wafer by rinsing the wafer with the rinsing agent comprises rinsing the wafer with deionized water.
 10. The method of claim 1, further comprising: removing the material comprising a residue from a semiconductor manufacturing process from the surface of the wafer, the residue comprising one of a chemical mechanical planarization process slurry material, a metal material, a photoresist material, dielectric material, and polysilicon material.
 11. The method of claim 10, wherein removing a metal material from the surface of the wafer includes removing a refractory metal from the surface of the wafer.
 12. Apparatus for etching a surface of an area of a wafer using a liquid material for preventing damage to surrounding semiconductor circuits comprising: a head including a tube having a bore therethrough and an exterior wall, the tube configured for supplying an etchant to a surface of a wafer, the tube including at least two inlets thereto; an annular member having an interior wall surrounding the tube, the annular member having at least one thin annular edge thereon for positioning adjacent a portion of the surface during the etching thereof for substantially forming a seal between the at least one thin annular edge and the surface, the annular member forming an annular space between the exterior wall of the tube and the interior wall of the annular member; and a source of vacuum connected to the annular space.
 13. The apparatus of claim 12, further comprising: an etchant comprising at least one of a liquid, a liquid vapor, and a gas comprising ammonia, hydrogen fluoride, nitric acid, hydrogen peroxide, ammonium fluoride, and mixtures thereof disposed in a container connected to the tube.
 14. The apparatus of claim 12, wherein a cross-section of the tube includes a cross-sectional shape comprising one of a circle, a hexagon, a square, an octagon, and an ellipse.
 15. The apparatus of claim 12, wherein a cross-section of the annular member includes a cross-sectional shape comprising one of a circle, a hexagon, a square, an octagon, and an ellipse.
 16. The apparatus of claim 12, wherein the tube comprises one of a metal tube and a non-metallic tube.
 17. The apparatus of claim 12, wherein the annular member comprises one of a metal annular member and a non-metallic member.
 18. The apparatus of claim 12, wherein the annular member includes an annular member having a plurality of thin annular edges thereon. 